The present invention relates to a ceiling light fitting for lighting a wall, known in the art as a "wall washer". The light fitting has means (which may be termed a chassis) for mounting the fitting in the ceiling, holding means for holding a lamp in the fitting and a reflector for directing reflected light towards the base portion of the wall.
The intention of ceiling light fittings of this type is to light a side wall of a room evenly from top to bottom and from side to side with a cut-off at the top so that there are no streaks of light along the ceiling; in practice, the eye will accept significant variations in illumination, but there is still a problem in directing enough light to the base of the wall to prevent it appearing rather darker than the top part. It is also required that the light fitting should be as unobtrusive as possible, that the light output should be used efficiently and that the light source itself should be shielded from sight of the occupants of the building. In many cases the most convenient place for the light fitting is to recess it in the ceiling above the wall to be illuminated. This creates some problems with the light distribution which must be solved in the design of the light fitting: the areas of the wall closest to the fitting are too brightly illuminated and the top edge of the wall is difficult to illuminate from a fitting recessed above the ceiling plane. Some existing fittings intended for this purpose for instance utilise lamps mounted vertically in reflectors in the ceiling fitting from which light is directed towards the bottom of the wall with a small reflector in the mouth of the fitting below the ceiling level which redirects some of the light towards the top of the wall; the reflector may be curved in two planes at right angles, projecting down beneath the lamp on the side of the lamp opposite to the wall. In another arrangement, a light with a parabolic reflector is used with a shield for hiding the filament or other light source of the lamp when one looks up at the fitting.
The problem with such lamps is that the illumination is greatest on the wall directly opposite the lamp and falls away rapidly--illumination tends to be poor at the base of the wall. If (as is usual) a number of lamps are used spaced along the ceiling, uneven illumination is obtained where beams are superimposed and at the edges of beams--one can obtain a pattern along the top portion of the wall like a cusped arcuate fringe. A further disadvantage of these arrangements is that the lamps project significantly below ceiling level and are rather obtrusive.
In general terms, the object of the invention is to provide an improved ceiling light fitting for lighting a wall and more particularly for ensuring adequate and even illumination at the base of the wall and at the top of the wall.